Welcome to the minimeter wiki!🥇
The whole project based on (https://www.instructables.com/member/VolosR/) little Nano based “semi” multi-meter solution on Instructables.com. and stephans nanOmeter project(Stephan/ProtoWrxs )
- Measure DC voltage (with reverse voltage diode protection)
- Read an analog input and show the value, as well as the min, max and average values
- Measure the resistance of a resistor
- Measure the voltage drop of a diode or LED (and test the LED there too)
- Act as a beeping / LED continuity tester
- Generate a PWM output
- Test a servo
- Test a ping / SR04 sensor
- Drive a stepper motor driver\
- Monitor the external battery supply voltage on the Vin pin
- Allow adjustments to the data dump timer (more later)
- Do an I2C bus scan and show attached device addresses.
(P) = PWM Pin
- 0 – Rx – On header pin lower right – Used to receive commands from serial console, etc
- 1 – Tx – On header pin lower right – Dumps CSV data to here
- 2 – Left Button
- 3(P)- Middle Button (on interrupt)
- 4 – Right Button
- 5(P)- Software Servo Pin
- 6(P)- PWM output on three pin header
- 7 – Ping Trigger
- 8 – Ping Echo
- 9(P)- Stepper IN1
- 10(P)- Stepper IN3
- 11(P)- Stepper IN2
- 12 – Stepper IN4
- 13 – Used for speaker output and LED display
- A0 – Main Analog Input
- A1 – Voltage Meter input – on 100k/10k divider
- A2 – Input for Diode and Resistor testing
- A3 – SPARE
- A4 – I2C bus
- A5 – I2C bus
- A6 – SPARE
- A7 – spare
I used original servo library since stephans Adafruit’s SoftServo library as the normal servo library kills some PWM pins and I wasn’t sure if they would be needed.The AdaFruit OLED library is used for the SSD1306 device which is the 128 x 32 pixel version. VolsR’s updated version uses the larger 128×64 version but personally I would love the minimalistic compact look for this project. Aslo to avoid measurement reading error from the touch ,i applied thick layer of hot-glue to the back of the circuit board.
To add the images I “temporarily borrowed” some icon art from online (I’ll give them back when I’m done) and converted them to the HEX format needed using the handy image2cpp online at at https://diyusthad.com/image2cpp. Works great and good enough results for me.
